This specification relates to additive manufacturing, such as fused filament fabrication (FFF) three dimensional (3D) printing, also known as Fused Deposition Modeling (FDM).
FFF using extruded polymer filament is useful for manufacturing three dimensional objects. Current FFF printing is typically accomplished by forcing a solid plastic feedstock through a heated nozzle. The filament is liquefied before or as it passes through the constriction in the nozzle, and the feed pressure causes a bead of material to be extruded as the nozzle is moved to form a beam of the material that is added, layer by layer, to build the object. 3D models of objects can be designed using computer-aided design (CAD) software and then converted to toolpaths for the nozzle of a 3D extrusion printer, either by the CAD software or separate software, often referred to as a slicer. In addition, various techniques have been employed to define toolpaths for infill material to be 3D printed inside an object to be manufactured by the 3D printer, as well as various techniques for defining toolpaths to create support structures for overhangs of an object to be manufactured by the 3D printer.